This fall, if you need an MRI or heart surgery, if you engineer computer chips for a living, build rockets, conduct scientific research, or if you do arc welding, you may suddenly have difficulty doing so.

All these functions require liquid helium.

As of the past Sunday, due to a lack of political will among our nation’s elected officials and miscommunication with business leaders, the world’s helium supply is suddenly at risk.

Two sources in the United States provide 50 percent of the world’s helium. Exxon’s Wyoming facility accounts for 20 percent of the total supply, and a planned shutdown from Sept. 1 through mid-October for maintenance and plant upgrades normally wouldn’t endanger helium supplies.

But 30 percent of the world’s helium is provided through a facility in Amarillo, Texas, administered by the U.S. Bureau of Land Management through the Federal Helium Program, which expires Oct 7.

All summer, members of Congress have debated the issue. Both houses have proposed bills, but they have not come to closure.

Perhaps they thought they had until October.

Wrong.

Since 1925, with the passage of the Helium Conservation Act, the U.S. government has played a significant role in producing, refining and storing helium.

National defense was the motivation as helium was used for military dirigibles and other classified applications. In 1996, Congress directed that the helium business should be privatized and set a date of Sept. 30, 2013, for the U.S. to withdraw from the expensive and delicate business of extracting helium.

Now, political stalemate and miscommunication have created this urgent situation.

Letters issued in August from the U.S. Bureau of Land Management (BLM), and from Praxair, a major helium supplier, reveal pressing news.

In an Aug. 12 letter from BLM to Praxair, the federal agency states that it will not be able to provide helium if Congress does not fund the Federal Helium Program beyond Oct 7.

Further, in an Aug. 22 letter to its customers, Praxair writes: “The BLM has notified Praxair of its preliminary contingency plans in the event funding expires by Oct. 7. According to the BLM, this will necessarily involve shutting down the CHEU (crude helium enrichment unit) and production wells as early as September 15, 2013, followed by a drawdown of the BLM pipeline.”

Helium is essential for many applications. MRIs that image cancer tumors use helium. Heart patients rely on helium for proper catheterization during surgery.

Helium is used in rocket engines, so it is vital for national defense and surveillance. Arc welders and scuba divers both use helium, so expect impacts to construction and to rescue operations.

Technology companies that design and produce fiber optics and computer chips use helium. And scientists, including chemists, need steady supplies to conduct research and critical lab tests that can take days or weeks to complete.

When liquid helium supplies vacillate, as they have in the past two years, this inconsistency drives up the cost of all of these functions and makes it nearly impossible to run important research at Stanford University, UC Berkeley, UC San Francisco Medical Center and other research facilities across our nation.

If the liquid helium supply were to suddenly vanish, much of our modern world would be thrown into a tailspin.

I urge Congress to present a bipartisan agreement that will allow the Federal Helium Program to continue operations for the time being. The need for helium is critical.

Marinda Li Wu of Orinda is president of the American Chemical Society. She wrote this for this newspaper.

In closed door talks, Sen. Dianne Feinstein agreed to a major new water policy for California that sells out the Delta and guts Endangered Species Act protections. Sen. Barbara Boxer is fighting the good fight to remove the rider from her comprehensive water infrastructure bill, but it may take a presidential veto.